Wax and compound heating apparatus



Feb. 10, 1931. D. s. LOCKWOOD 1,792,434

WAX AND COMPOUND HEATING APPARATUS Filed May 28, 1928 l/VVEN TOR.

4.3? BY 7M ATTORNEY.

Patented Feb. 10, 1931 UNITED STATES PATENT OFFICE DANIEL S. LOCKWOOD, OF THE UNITED STATES ARMY, WASHINGTON, DISTRICT OF COLUMBIA WAX AND COMPOUND HEATING APPARATUS Application filed May 28, 1928. Serial No. 281,279.

(GRANTED UNDER THE ACT OF MARCH 3 1883, AS AMENDED APRIL 30, 1928; 370 0. G. 757) This invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

5 This invention generically relates to an electrically controlied heating apparatus and more particularly it is directed to an assembly adapted to be utilized in the art of dentistry for the purpose of rendering plastic substances sufficiently pliable for proper manipulation.

One of the objects of this invention is to provide an apparatus of the character designated having facilities for constantly mainis taining a predetermined temperature range, the latter being predicated on the thermal requirements essential to the convenient manipulation of the plastic compounds employed by dentists in the pursuit of their profession.

Another object of this invention is to effect an apparatus adapted to provide a constant temperature range from the ordinary oiiice supply circuit without the application of auxiliary thermo-regulatory devices commonly resorted to for this purpose.

Another object of this invention is to furnish the dental practitioner with a simple, durable, inexpensive heating apparatus whose components are readily available on the market and easily and quickly combined to provide a heating apparatus of the type designated.

With these and other objects in view this invention consists in certain novel details of construction, combination and arrangement of parts to be more particularly hereinafter set forth and claimed.

Briefly stated, the cardinal factors of the 49 invention under consideration are an annular metallic body including in a unitary structure a centrally depressed portion constituting a water compartment for the plastic compound to be treated, a heating chamber surrounding the compartment, the top wall portion of said chamber being formed with seats for the reception of a pair of waX or paraflin melting cups, a pair of electr cal heating units located interior of the heating 5O chamber and supported immediately ad acent the water compartment and a base .l'nounting the metallic body and forming a glosure for the open end of the heating chamer.

Referring more particularly to the accompanying drawings in which corresponding parts are indicated by similar reference characters Fig. l is a perspective View of the heater constituting the subject matter of this application,

Fig. 2 is a section taken on the line 11 of Fig. 1, r

Fig. 3 is a bottom plan of the upper portion of the heater, the base being removed,

Fig. 4 is a sectionized view of one of the cups,

Fig. 5 is a bottom plan, the base 3 and electrical unit being removed,

Fig. 6 is a plan of the heating unit assembly and electrical connections therefor, and

Fig. 7 is a sectionized diagrammatic view of one of the electrical heating units.

Heretofore the dental practitioner has experienced considerable difiiculty in maintaining the various dental compounds at temperatures, which Would render them read ily workable throughout the period of his operations. Usually thermostatic devices were resorted to for this purpose but these required attention and unless closely super vised the compound became either too soft or hard for usage, whereupon the dentist was compelled to regulate the temperature until the compound obtained the desired consistency. This situation not only entailed loss of time but frequently a duplication of Work.

It is therefore the aim and purpose of this invention to provide a simple heating apparatus which may be plugged into the office supply circuit and which Will simultaneously heat bot-h the Wax and compound to the required extent and maintain it in this condition as long as desired.

In the illustrated embodiment characterizing this invention (1) indicates a metallic body preferably of aluminum and embodying a central depressed portion forming a water compartment (2) surrounded by a drawing.

heating chamber (3), the water compartment and heating chamber being defined by the laterally spaced inner and outer wall portions (4)- and (5), arcuate top portion (6) and bottom portion (7) of the water compartment as clearly shown in Figs. 1 and 2 of the drawing. r r

The ar'cuatelyshap'ed top wallport'ion (6) is formed with a pair of adjacently located openings (8) and the lowermostedge of the outer wall portion (5) is provided with a circumferentially extending bead- (9). The purpose of the openings (8) and bead (9) will be hereinafter referred to as this ,description proceeds.

A metal band (10) is positioned in heating chamber (3) in encirclingrelation with respect to inner'wall' portion (4) of the water compartment, the free ends of the band being united as at (11'). Band 10) passes through and supports a pair of heating units (12) and (12) in binding engagement with the contiguous surfaces of the innermost wall portion (4) as clearly shown in Fig. 3 of the Heating units (12) and (12') in the present instance are of a type Well known to the dental art and therefore it is deemed sufficient for the purpose of this disclosure to merely say each heating unit consists of inner and outer cylinders and (13) spaced to form a housing for the heating coils (14) and (14') the terminals of which are connected to binding posts and (16), (15) and (16), the latter bein-gconnected by conductors and ('18) and'(17) and (18) to coupling elements (19) and (20) which in turn by leans (21) and are connected to a plug (22) of conventional design.

The predetermined spaced relation 'of the respective heating units n the supporting band ('10) is maintained by anchoring wires (23 and (23) which span the heating units and have their extremities connected to the band as at (2 1) and (24).

Spacers of asbestos orli'lze material are positioned on the terminals (15) and (16') of the heating units and bridge the inner and outer wall portions (4 and (5) of the body (1) to prevent rotation of the heating units about the'bandas will be manifest without further discussion. Likewise an asbestos spacer (26) or similar material,- may be employed to prevent the contact, of leads (17) and (1 8) with adjacent metallic surfaces of the body;

Metallic body with parts assembled is positioned upon a base (27) which is provided with an overlying protective sheet (28) of asbestos or like material. Fastening elements extending through base (27), asbestos sheet (28,) and bead (9) effect a rigid union between said base and the metallic body mounted thereupon; Suitable openings (not shown) on base and asbestos covering serve to accommodate the passage of the leads to the plug (22).

Paraffin or wax melting cups (29)- are suspended in the heating chamber through openings (8) of the body (1) the extent to which the cups project in said extension chamber being determined by a rib (30) circumscribing each cup at a point adjacent its upper end. An apertured cover (31) is removably associated with the open end of the cups as clearly shown in Fig. 4 of the drawmg.

The heating capacity of the two electrical heating units, the area of the heating chamberand the dimensions of the water compartment are all so related that when said compartnient is partially filled with water its temperature will remain constant with a range of 150 to 160 F. As the working range of all compounds at present-utilized i'nthe practice of dentistry is between 115 to 150 F.

and asthe melting range of the parafi in from which this apparatus is designed is 112 to 130F. it is obvious an optimum temperature is readily maintained withoutthe use of thermostats or other regulatory devices for both waxes and compounds. Moreover, should the water compartment-become dry by evaporation, the heating effect of the respective units is not sufficient to damage the adjacent wall of the water compartment.

In conclusion it isevident this invention provides a heating apparatus of air exceeddepressed portionof the bodyinterior ofthe heating chamber, an electrical heating unit supported by said bandand a support ingbase for saidbody, the base constituting a closure for the bottom portion of the heatin'g'cha'mber. I 2. An annealing apparatus of the character described comprising a body formed of a metallic disc ha'vingits peripheral and ce'ntral' portion depressed in opposite directions to provide an annular water compartment and a st'i'rrounding heating chamber, a supporting band frictionall'y engaging the centra'lly depressed portion of the body interior of the heating chamber,- electrica'l h'eating units mounted upon the band in spaced relation and a supporting base for said body, the base constituting a closure for the bottom portion of the heating chamber.

3. An annealing apparatus of the character described comprising a body formed of a metallic disc having its peripheral and central portions depressed in opposite directions to provide a central Water compartment and a surrounding heating chamber, an attaching bead encircling the free edge of said body, Wax containers seated in said body and projecting to the interior of the heating chamber, heating units supported interior of the heating chamber, a base mounting the body and constituting a closure for the bottom of the heating chamber and means effecting a union between said base and bead.

4. An annealing apparatus comprising a body formed of a metallic disk and having its peripheral and central portions depressed in opposite directions to substantially the same plane to provide a water compartment, and a surrounding air chamber, electrical heating means Within the air chamber and a base having its upper surface in engagement with the peripherally and centrally depressed portions, said base forming a seal for the open end of the air chamber.

5. An annealing apparatus of the character described comprising a body formed of a metallic disk and having its peripheral and central portions depressed in opposite directions to substantially the same plane to provide a Water compartment, and a surrounding air chamber, a heating element supported upon the exterior surface of the water compartment and interior of the air chamber and a supporting base having its upper surface in engagement with the centrally and peripherally depressed portions, said base sealing the open end of the air chamber.

DANIEL S. LOCKWOOD. 

